Clinical evaluation of the opertive results for OPLL in cervical spine.

Since 1980, operative treatment was performed on 49 patients of OPLL associated with cervical myelopathy by means of laminoplasty (42 cases), laminectomy (2 cases) and anterior decompression (5 cases). The clinical results were evaluated using J. O. A. score of cervical myelopathy and recovery rate of Hirabayashi's method. The preoperative average was 10.8 points, and it was improved up to 14.0 points postoperatively. The recovery rate was 50.7%. The duration of myelopathy and age at the operation etc were the factors for affecting the results of operation. Radiological progression of OPLL was seen in 36.7%, but these radiological changes didn't affects the results. We have usually used surgical microscope in laminoplasty (modified Ito's method), so that we have had no neurological problems.